Mesozoic and Cenozoic Geology and Paleontology. 221. 
rocks, which lie beneath them all. At one place, in sinking a well, 
after passing through the surface deposits, blue clay was penetrated 
70 feet in thickness, followed by 18 feet of sand, gravel, and clay, be- 
low which a light-colored limestone was reached. There is ample proot 
that the Winnipeg basin has been filled with water to the foot of the 
second prairie steppe, in recent geological times. In digging wells in 
the city of Winnipeg, wood bark and leaves are sometimes met with, 
and fresh-water shells occur in the sand deposits between the south 
end of Lake Manitoba and the Assineboine river, about 50 feet above 
the former. The level of Lake Winnipeg above the sea is 710 feet, 
St. Martin’s lake 737 feet, Lake Manitoba 752 feet, Lake Winnipegosis 
and Cedar lake 770 feet, and Lake of the Woods 1,042 feet. 
The drift strie* in the eastern part of Wisconsin are exceedingly 
variable. Between the Kettle range and Lake Michigan, their course 
is from S. 4° W. to 8. 116° W. Between the Kettle range and the 
Green Bay and Rock River valley, their course is from 8. 12° W. to 
S. 59° KE. In the trough of the Green Bay and Rock River valley, 
their course is from 8. 41° W. to 8. 7° E. And on the west slope ot 
the Green Bay and Rock River valley, from 8. 94° W. to 8. 24° W. 
The diagram. used to illustrate the course of these striae, resembles the 
flowing vanes of an ostrich feather, with the shaft pointing to the 
northeast, 
The drift deposits are separated in ascending order, into: Ist—Bowl- 
der clay; 2d—Beach formation; 3d—Lower red clay; 4th—A beach 
formation; d5th—Upper red clay; 6th—Beach formations. The eleva- 
tion of the beach ridge which marks the western limit of these de- 
posits above Lake Michigan, near the Illinois line, is 55 feet; farther 
north, from 40 to 80 feet. North of Milwaukee there is a well-defined 
terrace, nearly parallel to the lake shore, from 50 to 100 feet high. In 
the vicinity of Sturgeon Bay, the terrace is replaced by a beach ridge 
of rather fine yellow sand. Along Green Bay, between Egg Harbor 
and the mouth of Sturgeon Bay, terraces of rock sustain a relation to 
the present shore similar to the terraces farther south. These rise, in 
some cases, almost vertically, to a height of more than 100 feet. The 
distance between them and the bay varies from a few rods to half a 
mile or more, and the interval is strewn with water-worn fragments of 
rock and occasionai slight beach ridges. 
In Central Wisconsin, the courses of the strize are not less variable, 
though but few have been observed. In Dane county, they vary from 
* Geo. of Wisconsin, vol. ii, 1877. 
